Diesel engine



Fab, 211, @330 H. c. EDWARDS 9 9 DIESEL ENGINE Filed Sept. 5, 1930 Patented Feb. 21, 1933 UNITED STATES PATENT? oFFIcE' HERBERT C. EDWARDS, F DETROIT, MICHIGAN, ASSIGNOR TO PACKARD MOTOR CAB COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN DIESEL Application filed September I ing smooth, unbroken surfaces for the passage of gas to or from the interior of the cylinder, where a two-part cylinder 1 head is used.

Other and further objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawing and following specification wherein is disclosed a single exemplary embodiment of the invention with the understanding, however, that such changes may be made therein as fall within the scope of the appended claims without departing from the spirit of the invention.

In said drawing: l I

Figure 1 is a plan view of a cylinder for internal combustion engines c'onstructed according to the present invention;

Figure 2 is a vertical section therethrough taken on line 2-2 of Fig. 1; and

' Figure 3 is a section at right angles to Fig. 2 and taken on line 33 thereof.

In the construction of internal combustion engines and particularly those intended for aviation use, it has beenthe custom to form the entire cylinder head separate from and sometimes of material difierent from that of the cylinder. Thus the cylinder may be cast.

' block and has attached thereto, for cooling purposes and to form gas passages, a separate cooling head formed of the same or different material. This latter form using a head, for instance oi aluminum, is particu- ENGINE 5, 1930. Serial No. 480,006.

ities and formed with integral fins 12, for

cooling, as is customary, although water coolmg may be used if desired; The cylinder head proper 13 is formed as an integral portion of the cylinder and is considerably thicker'than the side walls, as clearly shown, to

provide for the reception of studs 15 for securing the cooling head 16 thereto.

The form of cylinder shown in this example is of the single valve type wherein the valve is eccentric to the cylinder bore, as clearly shown in Fig. 1. The head 18 of the valve is within the cylinder proper and the seating portion 19 of the valve bears on the seat 20 which is chamfered from the wall 21 of a circular port 22 through the cylinder head 13.

The cooling head heretofore mentioned is preferably formed of aluminum or a suitable aluminum 'alloy of high heat conductivity where air-cooling is used and is provided with the fins 25 to increase its radiation. Where water cooling is used it may be of the same material as the cylinder. As before mentioned, it is secured to the cylinder by studs 15. It carries not only the valve stem guide but the valve springs and valve operating mechanism. To accommodate the valve stem 26 it is drilled as at 27 to receive the valve-stem guide-bushing 28 secured in position either by a press fit or a lock-nut 29 or both. The boss 30 which is drilled for the bushing 28 is in the bottom of a well 32, the walls 38 of which are integral with the cooling head. The valve stem has a large separable disc suitably secured thereto and between its overhanging portion and the annular bottom of the well 32 is arranged a plurality of valve springs 36 suitably guided on pins 37. A lateral enlargement 380f the well 32 accommodates the rockerarm 39 and other parts for operating the valve.

The valve, of course, controls the flow of air to the cylinder and exhausts products from the cylinder through the port 22. A combined inlet and exhaust manifold 42 may, in this form of the invention, be formed integral with the cooling head 16 and is arranged to have one end connected to an exhaust pipe and at the other end to receive air for mixture, in the cylinder, with the fuel.

It is highly desirable that the gas passage 44, in the head 16, between the manifold 42 and the port 22 be of such a character as to offer the least possible resistance to incoming and exhausting gases and at the same time to so direct the incoming gases as to obtain the maximum turbulence within the cylinder prior to and during explosion. For this reason the passage 44 is as nearly a venturi as possible and is inclined as much as possible to the valve stem. Not only that, but as seen in Fig. 1, it is directed more or less tangentially into the cylinder. In order that the head 16 be as compact as possible the passage is not circular in cross-section but is a flattened ellipse with its major transverse to the cylinder bore.

This passage 44, as shown in Fig.2, has a minimum height at" 45 but its width, as viewed in Fig. 1, is substantially uniform throughout its length. The change in height is arranged to be such that the cross-sectional area of the passage at any distance from the throat 45 conforms as nearly as possible to that of a theoretical venturi. A portion of the inner end of the passage must, of course, include a part of the port 22 and it can be seen at the right hand side thereof that a portion of the upper edge of the port wall is cut away as at 46 to conform to the passage. In addition to this, a lip 48 on the cooling head extends down into the port so that its surface forms a continuation of the upper surface 49 of the passage 44 so that the entering gas engages substantially a smooth, continuous wall from the manifold 42 to the valve seat 20, and encounters the minimum of resistance to its flow, the velocity of which must of necessity be high in an engine where the speed exceeds 2000 R. P. M.

This Ii 48 not only serves to conform the left han portion of the valve port to the configuration of the gas passage but by having the shoulder which' abuts the port wall 21 it materially aids in rapid assembly of the cooling head onto the cylinder for it accurately positions the two in respect to each other so that the fastening studs can be read- 11y placed in position.

If an attempt were to be made to form the cylinder head 13 with a part correspond ing to the lip 48 there would not only be the difficulty of machining the port and valve seat but the extreme thinness of the junction between the lip and the remainder of the cylinder head would be such that it would be Very likely to be broken either during the machining operation or later while in use.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In an internal combustion engine, in combination, a cylinder, an integral head portion having a port and valve seat, a valve cooperating with said seat, a cooling head secured to said integral head and having a valve stem guide, a passage through said cooling head communicating with said port at a large angle to the valve stem and a lip on said cooling head extending into said port to provide a smooth surface for the entering gases.

2. In an internal combustion engine, in combination, a cylinder having an integral head portion, a cylindrical port and valve seat in said head, a valve cooperating with said seat and having a stem projecting through said port, a cooling head secured to said integral head and having a valve stem guide, a gas passage in said cooling head communicating with said port at a large angle to the port axis, and means on said cooling head entering said port at the side thereof opposite the gas passage to form a continuation of the gas passage'wall substantially to the valve seat.

3. In an internal combustion engine, in combination, a cylinder having an integral head provided with a cylindrical port and an internal valve seat, a cooling head secured to said integral head and having a Venturi passage to said valve port with its walls substantiallv formed by the material of said cooling head, and means on said cooling head extending the passage configuration through the port to the valve seat.

4. In an internal combustion engine, in combination, a' cylinder, a head therefor having a port and an inside valve seat, a stemmed poppet valve cooperating with said seat, a cooling head rigidly secured to said other head, a passage through said cooling head communicating with said port at an angle to the port axis, and means on said coolinghead extending said passage into said port.

In testimony whereof I hereunto afiix my signature.

HERBERT C. EDWARDS. 

